fix(plugin-mysql): make socket read timeout follow the query timeout

CHANGELOG.md

@@ -14,6 +14,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 
 - Windows Authentication (Kerberos) to SQL Server now works on macOS. The bundled SQL Server driver was built without Kerberos support, so every Windows-auth connect failed as if the credentials were wrong. (#1918)
+- MySQL and MariaDB queries no longer fail after about a minute when a longer query timeout is set. The client read timeout now follows the configured query timeout, so a long query or stored procedure runs for the full time you allow. (#1921)
+- A dropped MySQL or MariaDB connection no longer silently re-runs a statement that changes data, so a lost connection can no longer run an insert, update, or stored procedure twice. (#1921)
 - The MongoDB, Oracle, Cassandra, and Elasticsearch plugins failed to install on 0.58 with "Bundle failed to load executable". (#1917)
 
 ## [0.58.0] - 2026-07-18

Plugins/MySQLDriverPlugin/MariaDBPluginConnection.swift

@@ -67,7 +67,7 @@
 func mysqlTypeToString(_ fieldPtr: UnsafePointer<MYSQL_FIELD>) -> String {
     let field = fieldPtr.pointee
     let flags = UInt(field.flags)
     let length = field.length
 
     // MariaDB extended metadata: detect JSON stored as LONGTEXT.
     // `MARIADB_CONST_STRING` is length-prefixed (not null-terminated), so we must read
@@ -159,6 +159,7 @@
     private let database: String
     private let sslConfig: SSLConfiguration
     private let enableCleartextPlugin: Bool
+    private let queryTimeoutSeconds: Int
 
     private let stateLock = NSLock()
     private var _isConnected: Bool = false
@@ -192,7 +193,8 @@
         password: String?,
         database: String,
         sslConfig: SSLConfiguration,
-        enableCleartextPlugin: Bool = false
+        enableCleartextPlugin: Bool = false,
+        queryTimeoutSeconds: Int = 0
     ) {
         self.host = host
         self.port = UInt32(port)
@@ -201,6 +203,7 @@
         self.database = database
         self.sslConfig = sslConfig
         self.enableCleartextPlugin = enableCleartextPlugin
+        self.queryTimeoutSeconds = queryTimeoutSeconds
     }
 
     deinit {
@@ -261,10 +264,10 @@
         var timeout: UInt32 = 10
         mysql_options(mysql, MYSQL_OPT_CONNECT_TIMEOUT, &timeout)
 
-        var readTimeout: UInt32 = 30
+        var readTimeout = mysqlSocketTimeoutSeconds(forQueryTimeout: queryTimeoutSeconds)
         mysql_options(mysql, MYSQL_OPT_READ_TIMEOUT, &readTimeout)
 
-        var writeTimeout: UInt32 = 30
+        var writeTimeout = mysqlSocketTimeoutSeconds(forQueryTimeout: queryTimeoutSeconds)
         mysql_options(mysql, MYSQL_OPT_WRITE_TIMEOUT, &writeTimeout)
 
         var protocol_tcp = UInt32(MYSQL_PROTOCOL_TCP.rawValue)

Plugins/MySQLDriverPlugin/MySQLPluginDriver.swift

@@ -79,7 +79,8 @@ final class MySQLPluginDriver: PluginDatabaseDriver, @unchecked Sendable {
             password: config.password,
             database: _activeDatabase,
             sslConfig: sslConfig,
-            enableCleartextPlugin: config.additionalFields["enableCleartextPlugin"] == "true"
+            enableCleartextPlugin: config.additionalFields["enableCleartextPlugin"] == "true",
+            queryTimeoutSeconds: config.additionalFields["queryTimeoutSeconds"].flatMap { Int($0) } ?? 0
         )
 
         try await conn.connect()
@@ -193,7 +194,8 @@ final class MySQLPluginDriver: PluginDatabaseDriver, @unchecked Sendable {
                 isTruncated: result.isTruncated,
                 columnMeta: result.columnMeta
             )
-        } catch let error as MariaDBPluginError where !isRetry && isConnectionLostError(error) {
+        } catch let error as MariaDBPluginError
+            where !isRetry && isConnectionLostError(error) && mysqlStatementIsReadOnly(query) {
             try await reconnect()
             return try await executeWithReconnect(query: query, isRetry: true, rowCap: rowCap)
         }

Plugins/MySQLDriverPlugin/MySQLSocketTimeout.swift

@@ -0,0 +1,13 @@
+//
+//  MySQLSocketTimeout.swift
+//  MySQLDriverPlugin
+//
+
+internal let mysqlSocketTimeoutGraceSeconds = 30
+
+internal func mysqlSocketTimeoutSeconds(forQueryTimeout queryTimeoutSeconds: Int) -> UInt32 {
+    guard queryTimeoutSeconds > 0 else { return 0 }
+    let ceiling = Int(UInt32.max) - mysqlSocketTimeoutGraceSeconds
+    let clamped = min(queryTimeoutSeconds, ceiling)
+    return UInt32(clamped + mysqlSocketTimeoutGraceSeconds)
+}

Plugins/MySQLDriverPlugin/MySQLStatementClassification.swift

@@ -0,0 +1,17 @@
+//
+//  MySQLStatementClassification.swift
+//  MySQLDriverPlugin
+//
+
+internal func mysqlStatementIsReadOnly(_ query: String) -> Bool {
+    let keyword = query
+        .drop(while: { $0.isWhitespace })
+        .prefix(while: { $0.isLetter })
+        .uppercased()
+    switch keyword {
+    case "SELECT", "SHOW", "DESCRIBE", "DESC":
+        return true
+    default:
+        return false
+    }
+}

TablePro.xcodeproj/project.pbxproj

@@ -532,6 +532,8 @@
 			isa = PBXFileSystemSynchronizedBuildFileExceptionSet;
 			membershipExceptions = (
 				MySQLQueryTimeoutStatement.swift,
+				MySQLSocketTimeout.swift,
+				MySQLStatementClassification.swift,
 			);
 			target = 5ABCC5A62F43856700EAF3FC /* TableProTests */;
 		};

TablePro/Core/Database/DatabaseDriver.swift

@@ -473,6 +473,7 @@ enum DatabaseDriverFactory {
             }
             additionalFields["enableCleartextPlugin"] = "true"
         }
+        additionalFields["queryTimeoutSeconds"] = String(AppSettingsManager.shared.general.queryTimeoutSeconds)
         let config = DriverConnectionConfig(
             host: connection.host,
             port: connection.port,

TableProTests/Plugins/MySQLSocketTimeoutTests.swift

@@ -0,0 +1,35 @@
+//
+//  MySQLSocketTimeoutTests.swift
+//  TableProTests
+//
+
+import Testing
+
+@Suite("MySQL Socket Timeout")
+struct MySQLSocketTimeoutTests {
+    @Test("No limit maps to an infinite socket timeout")
+    func noLimitIsInfinite() {
+        #expect(mysqlSocketTimeoutSeconds(forQueryTimeout: 0) == 0)
+    }
+
+    @Test("A negative query timeout maps to an infinite socket timeout")
+    func negativeIsInfinite() {
+        #expect(mysqlSocketTimeoutSeconds(forQueryTimeout: -5) == 0)
+    }
+
+    @Test("A finite query timeout adds the grace period")
+    func finiteAddsGrace() {
+        #expect(mysqlSocketTimeoutSeconds(forQueryTimeout: 60) == 90)
+        #expect(mysqlSocketTimeoutSeconds(forQueryTimeout: 600) == 630)
+    }
+
+    @Test("The grace period is applied on top of the query timeout")
+    func graceMatchesConstant() {
+        #expect(mysqlSocketTimeoutSeconds(forQueryTimeout: 1) == UInt32(1 + mysqlSocketTimeoutGraceSeconds))
+    }
+
+    @Test("A very large query timeout clamps without overflowing")
+    func largeValueClamps() {
+        #expect(mysqlSocketTimeoutSeconds(forQueryTimeout: Int.max) == UInt32.max)
+    }
+}

TableProTests/Plugins/MySQLStatementClassificationTests.swift

@@ -0,0 +1,48 @@
+//
+//  MySQLStatementClassificationTests.swift
+//  TableProTests
+//
+
+import Testing
+
+@Suite("MySQL Statement Classification")
+struct MySQLStatementClassificationTests {
+    @Test("SELECT is read-only")
+    func selectIsReadOnly() {
+        #expect(mysqlStatementIsReadOnly("SELECT * FROM users"))
+    }
+
+    @Test("Leading whitespace and lowercase are handled")
+    func whitespaceAndCase() {
+        #expect(mysqlStatementIsReadOnly("   \n select 1"))
+    }
+
+    @Test("SHOW, DESCRIBE, and DESC are read-only")
+    func showAndDescribe() {
+        #expect(mysqlStatementIsReadOnly("SHOW TABLES"))
+        #expect(mysqlStatementIsReadOnly("DESCRIBE users"))
+        #expect(mysqlStatementIsReadOnly("DESC users"))
+    }
+
+    @Test("Mutating statements are not read-only")
+    func mutatingStatements() {
+        #expect(!mysqlStatementIsReadOnly("INSERT INTO users VALUES (1)"))
+        #expect(!mysqlStatementIsReadOnly("UPDATE users SET name = 'a'"))
+        #expect(!mysqlStatementIsReadOnly("DELETE FROM users"))
+        #expect(!mysqlStatementIsReadOnly("CALL do_work()"))
+        #expect(!mysqlStatementIsReadOnly("REPLACE INTO users VALUES (1)"))
+        #expect(!mysqlStatementIsReadOnly("DROP TABLE users"))
+    }
+
+    @Test("A statement behind a leading comment is treated conservatively")
+    func leadingCommentIsConservative() {
+        #expect(!mysqlStatementIsReadOnly("/* note */ SELECT 1"))
+        #expect(!mysqlStatementIsReadOnly("-- note\nSELECT 1"))
+    }
+
+    @Test("An empty statement is not read-only")
+    func emptyIsNotReadOnly() {
+        #expect(!mysqlStatementIsReadOnly(""))
+        #expect(!mysqlStatementIsReadOnly("   "))
+    }
+}